Has anyone ever had a MPFI that idled erradically because of carboned-up throttle plates? A mechanic friend of mine told me that this is a common problem with this type of fuel injection.

 

The way the EGR is routed, carbon gets through our intakes. Buy a bottle of "throttle body and intake cleaner for fuel injected engines" and follow the directions on the can. Carb cleaner is more "harsh" to our engines, and while it can be used, you might not want to. I've only used the "for fuel injected engines" cleaners.

Also clean your IAC (Idle Air Control) pintle and passageway; this little motor controls your idle. When the pintle and passageway get gunked up, the idle airflow isn't as much as the computer thinks it is.

See more info by clicking here: https://www.thirdgen.org/techbb2/sho...hreadid=175177 That'll tell you how to clean it all.

 

Actually, I changed the IAC over the weekend. My mechanic friend told me the best way to clean the throttle body is to remove it from the plenum. Just by looking at it , it really doesn't look too hard to remove. The only PITA is see is the coolant hoses that have to be removed.

I'm still sort of skeptcial about this causing my poor idling problem , but then again I'm used to working on carb's. I have been browsing through these forums and I didn't come across anyone ever having a carbon build-up problem with their throttle body.

I hope that I'm proven wrong.

 

Did you also clean out the IAC passageway, though? You might've just replaced a perfectly good motor... keep the old one as a spare!